Outside Klara Strand café, two green kayaks are lined up against the wall. They are marked with the text Green Kayaking, which is the Danish organization that in 2017 first started offering chatter in Copenhagen.

Klara Strand café is one of several distributors in Stockholm where you can borrow the kayaks for a few hours completely free of charge - in exchange for picking up rubbish during the paddle trip.

- There are very many who are interested, and most find a lot of rubbish. The bucket comes back full every other time or so, says Nicholas Eriksson, who runs Klara Strand café.

Sources themselves

So far, almost 100 kilos of rubbish has been collected at Klara Strand café during the little over a month that they have been offered loading. And when the rubbish is handed in to Nicholas Ericsson, he takes care of it himself.

- What is not too small, we sort at source, the rest is sorted as combustible, says Nicholas Eriksson.

Do you get any financial support for doing this?

- No, god no. It is private forces that clean up Stockholm's waters, says Nicholas Eriksson. 

Watch when SVT Stockholm tried chatter in the video above.